A field effect nano-pillar transistor has a pillar shaped gate element incorporating a biomimitec portion that provides various advantages over prior art devices. The small size of the nano-pillar transistor allows for advantageous insertion into cellular membranes, and the biomimitec character of the gate element operates as an advantageous interface for sensing small amplitude voltages such as transmembrane cell potentials. The nano-pillar transistor can be used in various embodiments to stimulate cells, to measure cell response, or to perform a combination of both actions.